Just 10 years ago, most high-quality bikes sold in the United States were made from aluminum or related alloys. As recently as 2003, our annual Buyer’s Guide featured only a handful of ­carbon-fiber models. And in the first years of this century, pros rode aluminum race bikes alongside carbon-fiber models at the sport’s most celebrated events.

Then the carbon-­composite craze took hold and so commenced the great aluminum disappearing act. High-end road bikes were the first to go. Top-of-the-line hardtail mountain bikes were next, quickly followed by suspension and midpriced bikes. Aluminum’s 20-year run at the pinnacle of the sport ended with shocking abruptness.

By 2005, most manufacturers had relegated aluminum to value models and hybrids, but a few continued to build impressive frames out of it. More recently, improvements to the way the metal can be manipulated have led to better-performing bikes, encouraging large and small builders to re-embrace aluminum’s value and performance. Nowadays, the material increasingly occupies an important niche between entry-level models and expensive carbon machines, in both road and mountain bikes. And there are few signs that aluminum’s resurgence will slow.

Elements of Choice
The earliest widely available aluminum frames were made in the mid-1970s by brands like Vitus and Alan. They were built with straight-gauge tubing that was similar in diameter to the steel tubes commonly used at the time. These so-called “glued and screwed” frames (a reference to their construction, which relied on mechanical joints rather than welds) had a pleasant ride quality, but were overly flexy, making them scary on descents and ineffective in sprints.

Cannondale and Klein pioneered aluminum 2.0 in the 1980s and early ’90s—the light, stiff frames were TIG-welded from thin, large-diameter,­ straight-wall tubes. Oversize aluminum frames ­originally were designed for durability, says Chuck Teixeira, a 28-year veteran of Easton’s materials department who now directs advanced R and D for Specialized. But extending the life span of the bikes came with an unintended consequence: an immense stiffness that created a harsh ride. As a result, the metal earned a bad rap that has proven hard to shake, even though stiffness isn’t an inherent property of the material.